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Impedance maps of acupuncture points

Authors:
  • VUJE, a.s. Trnava, Slovakia
Impedance maps of acupuncture points
Michal Teplan1,5, Marek Kukučka2,5, Alena Ondrejkovičová3, Boris Ivanič4,5
1Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
2Institute of Automotive Mechatronics, Slovak University of Technology, Bratislava
3Department of acupuncture, Faculty of medicine, Slovak medical university, Bratislava
4Clinics of anesthesiology and intensive medicine, Children’s faculty hospital, Bratislava
5Center for Advanced Human Studies, Bratislava
Visualization of acupuncture points
Aim
Although application of acupuncture is relatively well established in
Western medicine as a complementary therapeutic tool, its physical and
medical characterization is still largely unknown.
Several previous studies showed that acupuncture points may be
characterized by lower electrical impedance and higher capacity.
Purpose
Systematic review by Ahn et al. [1] concluded that it is still impossible
to determine whether acupuncture structures possess distinct electrical
characteristics until better quality studies are performed.
Colbert [2] calls for precise replication of historical study of Becker et al.
[3].
Are very limited results of Becker et al. (1976) the corner stones of the
whole (physical electro-) acupuncture research?
Relevance
Impedance maps were measured with a grid of 64 brass needle elec-
trodes. Telescopic tips maintain balanced pressure across measured
area covering 17.5 mm x 17.5 mm (Fig.1). Monopolar arrangement was
applied with clamp reference electrode placed on the opposite arm
(surface 6 cm2). Frequency 1 kHz was used for probing current. Unique
recording system was controlled from Matlab environment via USB port.
The device measured voltage difference between active and reference
electrodes based on spike detector.
Development of a new procedure that would enhance visualization of
acupoints: We introduced concept of differential maps:
The experimental protocol includes impedance map measurements before,
during, and after stimulation of acupuncture system. Then subtraction of
maps obtained after and before stimulation is calculated. As one of the
modalities, electro-acupuncture stimulation was used. Impact of different
frequencies of stimulation will be further studied, also with regard to
meridian excitation or inhibition.
Fig.1: Left: Needle electrode probe with telescopic tips. Right: Measuring
unit with probe head and reference electrode.
Methods and analysis
Data from several subjects covered impedance maps from up to 10
different acupoint sites located on upper limbs.
Results appeared to be inconsistent in terms of reliable localization
of acupoint structures by means of spatial distribution of electrical
impedance.
Strictly isolated depression of impedance modulus surrounded by circular
patterns was not found in most of the maps, however in some cases there
was clear indication of it (Fig.2) [4].
Several acupoints were localized as a region with increased impedance
values (Fig. 2).
Differential map samples promise improved distinction of impedance
structures in acupoint maps (Fig.3).
Fig.2: Samples of impedance maps of acupuncture points measured at 1
kHz. Left: Typical impedance variations without successful localization of
acupoint. Middle: 3D view of decreased impedance of possible HT7 point.
Right: Increased impedance in the area of PC6 point.
Fig.3: Procedure for enhanced visualization, Li4 point: Differential map
(right) is produced by subtraction of the two previous maps obtained
during and before electro-acupuncture stimulation.
Results
In this research area we struggle with number of sensitive and variable
conditions of measurement.
Gradual improvement of complex methodology and measurement proce-
dure procedure (proper acupoint localization, skin preparation, electrode
properties, stimulation parameters, as well as measurement unit up-
grades) gives a chance that consistent localization of acupuncture points
by means of distinct electrical properties might not only be feasible,
but also may provide bases for invaluable diagnostic and therapeutic
applications.
Conclusions
[1]: Ahn AC et al.: Electrical properties of acupuncture points and meridians:
a systematic review. Bioelectromagnetics 29: 245-256, 2008.
[2]: Colbert A: The Ongoing Debate: Do Acupuncture Points Have Lower
Skin Resistance Than Nonacupuncture Sites? The Journal of Alternative
and Complementary Medicine 15 (10): 1059-1059, 2009.
[3]: Becker R et al.: Electrophysiological correlates of acupuncture points
and meridians. Psychoenergetic Systems 1: 195-212, 1976.
[4] Teplan M, Kukučka M, Ondrejkovičová A: Impedance analysis of acupunc-
ture points and pathways. Journal of Physics: Conference Series, vol. 329,
2011.
Literature cited
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Investigation of impedance characteristics of acupuncture points from acoustic to radio frequency range is addressed. Discernment and localization of acupuncture points in initial single subject study was unsuccessfully attempted by impedance map technique. Vector impedance analyses determined possible resonant zones in MHz region.